In order to solve this problem, it can help to empty the cache of your browser.

1. Click on the three horizontal dots on the right next to the URL.
   
2. Chose “More tools” in the menu.
   
3. Click on “Delete browsing data”. Chose the time range “All time”.
   
4. Make sure that you also chose “Cached images and files”
   
5. Click on “Clear data”.
   

Empty your cache in Mozilla Firefox:

1. Click on the three horizontal lines next to the URL.
   
2. Click on “Options” and chose “Privacy & Security”
   
3. You can see how much space is blocked under “Cookies and Site data”. 
   
4. Click on “Clear Data”.

Empty your cache in Safari:

1. Click on “Safari” on the left
   
2. Click on “Preferences” and afterwards on “Advanced”.
   
3. Check the option "Show Develop menu in menu bar" at the bottom. Now you should see a new menu item in the main menu named "Develop".
   
4. If you click on the menu item "Develop" you can select "Empty Caches" from the submenu items.